Method and apparatus for cleaning metal strips



July 12, 1955 G. DURST 2,713,011

METHOD AND APPARATUS FOR CLEANING METAL STRIPS Original Filed June 7, 1950 United States Patent METHOD AND APPARATUS FOR CLEANING METAL STRlPS George Durst, Attleboro, Mass assignor to Metals and Controls Corporation, Attleboro, Mass, a corporation of Massachusetts Continuation of abandoned application Serial he. 166,631, June 7, 1950. This application February 24, 1954, Serial No. 412,151

6 Cbims. (Cl. 134-415) This invention relates to methods and apparatus for cleaning metal strips and more particularly to a method and apparatus for cleaning the opposed faces of two metal strips which are to be solid-phase-bonded .in a rolling mill.

This application is a continuation of my copending application Serial No. 166,631, filed June 7, 1950, for Method and Apparatus for Cleaning Metal Strips, now abancloned.

The object of the invention is the provision of a method and apparatus for efiectively sweeping clean the opposed faces of two metal strips which are to be solid-phasebonded in a rolling mill prior to entry of the strips between the rolls of the mill to insure bonding of the strips. Is has been found that the opposed surfaces of two metal strips which are to be solid-phase-bonded by rolling must be clean and dr when they enter between the rolls of the mill to obtain a good bond. This invention provides apparatus for effectively sweeping clean the opposed surfaces of the two strips as they travel toward and just before they enter the mill so that these surfaces are clean as the strips pass between the rolls. In general, an apparatus of this invention includes a chamber having inlet and outlet openings for the two metal strips travelling toward i the rolling mill. Within the chamber is a means for sweeping the opposed faces of the metal strips as they travel'through the chamber on opposite sides of the sweep ing means. Dust swept from the strips by the sweeping means is discharged from the chamber so that it does not settle back on the strips. As herein illustrated, the means for sweeping the strips may consist of a gaseous blast device, such as an air blast device, and it is expected that other sweeping devices may be found suitable for the purpose. Other features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. l is a side elevation of an apparatus embodying the invention, illustrating two metal strips travelling through the apparatus and the rolls of a mill;

Fig. 2 is an enlarged partial plan view of Fig. l as viewed from the line 22 of Fig. l

Fig. 3 is a vertical longitudinal section of the Fig. 1 apparatus taken on line 3-3 ofFig.'2;

Fig. 4 is an enlarged vertical transverse section taken on line 44 of Fig. 2;

Fig. 5 is an enlarged vertical transverse section taken on line 55 of Fig. 3; and,

Fig.6 is an enlarged vertical transverse section taken on line 6--6 of Fig. 3.

Similar reference characters indicate corresponding parts throughoutthe several .viewsof the drawings.

Referring to the drawings, there is shown at 1 in Fig. 1 the rolls of a conventional rolling mill for solid-phasebonding two metal strips -3 and 5 to form a composite strip 7. Exemplary of metals to be bonded are stainless steel and copper. It will be understood, however, that the invention is applicable to the solid-phase-bonding of many other combinations of metals. In travelling to the rolls, the strips travel through a cleaning apparatus of this invention, generally designated 9, thence through a guide 11, and are squeezed together by the rolls upon emergence from the guide. Details of the guide are of no importance as far as this invention is concerned and are not herein illustrated or described. A guide suitable for the purpose is disclosed in the copending application of George Durst, entitled Strip Guide, Serial No. 180,830, filed August 22, 1950, eventuated as Patent No. 2,700,907 February 1, 1955.

The cleaning apparatus 9 illustrated in Figs. 1 6 comprises an elongate chamber 13 having a top wall 15, a bottom wall 37, and vertical side walls 19 and 21. At one end of the chamber is a strip inlet throat 23 defining a strip inlet opening 25. At the other end of the chamber is a strip outlet throat 2'7 defining a strip outlet opening 29. The top, bottom and sides of the throats are constituted by integral portions of the top, bottom and side walls of the chamber. The chamber and throats, as illustrated, are rectangular in transverse section and somewhat wider than the width of the strips to be cleaned, the structure being of constant width through the length of the inlet throat, the chamber, and the outlet throat. The top and bottom walls of the chamber converge from an intermediate and deepest zone of the chamber to the ends thereof for transition into the throats. Thus, the depth of the chamber diminishes from a deepest intermediate portion toward the ends thereof.

The strip inlet opening 25 and inlet throat 23 are somewhat wider than the strips and just deep enough for the strips easily to enter the chamber with one strip spaced somewhat above the other. The strip outlet throat 27 and outlet opening 29 are somewhat wider than the strips and just deep enough for the strips to travel through the throat and out through the opening with their opposed faces in contact. As illustrated, the inlet throat 23 is short in relation to the length of the chamber and the outlet throat 27 is considerably longer than the inlet throat. I V v i The strips 3 and 5 travelling through the chamber pass on opposite sides of a means 31 for dry-sweeping the opposed faces of the strips, strip 3 passing above this means and strip 5 passing below. As illustrated in Figs. 24, this means is an air blast device comprising an air blast pipe 33 extending transversely across the deepest part of the chamber generally at the center of the depth of the chamber and in line with the inlet and outlet throats. The pipe is fixed adjacent one end in a closure plate 35 which covers an opening 37 in the side wall 19 of the chamber. The plate 35 has top and bottom flanges 39 and 41 engaging over and under the top and bottom walls 15 and 17, respectively, of the chamber. The plate is held in position closing the opening 37 by latch members 43 pivoted on the outside of the side wall 19 of the chamher. The plate, together with the pipe 33, may be removed from the chamber by swinging the latch members to releasing position.

A flexible compressed air conduit 45 is connected to theopen end of the pipe which extends from the chamber through the closure plate. The pipe extends from the plate across the chamber and through an opening 47 in the side wall 23. of the chamber. Its free end extending through opening 47 is closed, and preferably tapered or pointed as indicated at 49 to facilitate entry in the opening 47, in which the pipe has .a close sliding fit,,and also to facilitate insertion of thepipe between the strips 3 and 5. Where the walls of the chamber are of thinsheet metal, as herein illustrated, a reinforcing collar 51 may be fixed to the outside of the side wall 21 of the chamber surrounding the opening 47 to reinforce the side wall and to provide additional bearing support for the pipe. A similar collar 53 may be used on the closure plate 35. The pipe is formed with a single row of air outlet apertures 55 directed toward the inlet throat 23 of the chamber.

. .The outlet opening 29 is maintained substantially sealed against entry or escape ofv air by upper and lower flexible sealing members 57 and 59 in wiping engagement with the outside faces-of the strips 3 and 5 respectively. Each sealing member, for'example, may consist of a strip of rubber or the like, with the upper member secured to a the lower member secured .to a flange 63 on the bottom of the outlet throat at its end. The chamber is provided with an air inlet 65 in its top wall between the cleaning means 31 and the entrance to the'outlet throat 27. A

a compressed air pipe 67 is coupled to this air inlet.

In the operation of the above-described apparatus, the closure plate 35 is removed to withdraw air pipe 33 from the chamber. The strips 3 and 5 are then threaded through the chamber. The pointed end of the pipe 33 is inserted between the strips and'the free end of the pipe is inserted in the opening 4-7. This brings the closure plate 35 into position closing the opening 37-, and the plate is latched in this position by latch members 43. Relatively high pressure air (80 p. s..i., for example) is supplied 'flange. 61 on the top of the outlet throat at its end and i to the pipe 33 through the flexible conduit 45 and lower Y pressure air is supplied to the chamber through inlet 65 from pipe 67.

' As the strips are pulled through the chamber by the rolling mill, the blasts of air through the air outlets 55 in the pipe 33' sweep the opposed faces of the strips 3 and 5 clean of any dust. The dust swept from the strips is discharged from the chamber through the inlet opening 25. It will be observed that the flow of air which is sweeping dust'from the opposed surfaces of the strips is opposite to the direction of travel of the strips. This is an important feature. The counterflow of air insures that dust swept from the strips is all blown away from A a the outlet end of the chamber toward and out of the inlet cling to the opposed faces of the strips are subjected to 1 a stronger and stronger blast as they approach the pipe 33 until ultimately they are blown olf and go out through the opening 25. It is probable that the bulk of the dust is removed near opening 25 and that less and less dust remains to be removed as the strips progresstoward the pipe 33.

While the counter-flow of air tends to draw room air into the chamber 13through the outlet opening 29, entry of room air, which may carry dust, through opening 29 is prevented by the maintenance of positive pressure in the chamber toward its outlet end by the air supplied through the air inlet 65. Thus, it is insured that the strips arrive at the rolls of the rolling mill with their opposed faces substantially clean of dust.

It will be understood that'itis preferable to use filtered air for blast-sweeping the strips. It will also'be understood that the invention is not limited to the use of air for the blast, but that other gases might 'be used, for example inert gases, or possibly hydrogen gas. Under some circumstances, it may be preferable to use hot air to avoid deposition of moisture on the opposed faces ofithe strips.

7 ln view of the above, it will be seen that the several ob ects of the invention are achieved and other adva tageous results attained.

.4 a As many changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim: 7 V

1. Apparatus for cleaning the inwardly opposed faces of two strips travelling in spaced face-to-face' relation, comprising means defining a chamber having a strip inlet and a strip outlet end, said means having an opening in one side to the chamber, a removable closure for the side opening, a pipe carried by and removable with the closure extending across the chamber in position for the two strips to travel on opposite sides thereof, said pipe having a free end formed for ready insertion between the strips and having gas outlet apertures directed toward the inlet end of the chamber adapted to emit a blast of gas directed toward the inlet end of the chamber to blast the entire width of the inwardly opposed faces of both strips to sweep dust therefrom, the gas emitted from the blast device flowing between the strips in the direction opposite to that of travel of the strips toward and out of the inlet end of the chamber to avoid redeposition of dust on the strips. j

2. Apparatus as setjforth in claim 1 wherein the said free end of the pipe is tapered, and the pipe extends through and has a close sliding fit in an opening in the other side of the chamber means.

3. The method of cleaning the inwardly opposed faces of two continuous strips travelling continuously in spaced face-to-face relation to a region where they are brought together in face-to-face engagement, comprising sweeping dust from the opposed faces of the strips by a blast of clean gas introduced into the space between the strips at a zone rearward of their region ofengagement and directed rearward with respect to the direction of travel of the strips, and confining the space between the strips from their region of engagement rearward past the zone other, the inlet being dimensioned for entry of the strips in spaced face-to-face relation, and the outlet being pro vided with sealing means engageable with the strips maintaining them in face-to-face engagement and substantially sealing the housing against entry of outside air through the outlet, and a'gas blast device extending across the housing from one side of the housing in position for the two strips to travel on opposite sides thereof and adapted to emit a blast of gas directed toward the inlet to blast the entire width of; the inwardly opposed faces of both strips to sweep dust therefrom, the gas emitted from the blast device being confined by the side walls of the housing to flow between the strips toward and out of the inlet.

5. Apparatus as set forth in claim .4 wherein the gas blast device comprises a pipe extending completely across the housing having gas outlet apertures directed toward the housing inlet.

6. Apparatus as set forth in claim 4, further comprismg meansfor introducing a gas under pressure into'the housing at a point between the gas blast device and the outlet to maintain a positive pressure in the housing and prevent 1 air from being drawn in through the outlet.

' Higgins May 28, 1929 Chapman Ian; 23, .1945 

1. APPARATUS FOR CLEANING THE INWARDLY OPPOSED FACES OF TWO STRIPS TRAVELLING IN SPACED FACE-TO-FACE RELATION, COMPRISING MEAND DEFINING A CHAMBER HAVINGG A STRIP INLET AND A STRIP OUTLET END, SAID MEANS HAVING AN OPENING IN ONE SIDE TO THE CHAMBER, A REMOVABLE CLOSURE FOR THE SIDE OPENING, A PIPE CARRIED BY AND REMOVABLE WITH THE CLOSURE EXTENDING ACROSS THE CHAMBER IN POSITION FOR THE TWO STRIPS TO TRAVEL ON OPPOSITE SIDES THEREOF, SAID PIPE HAVING A FREE END FORMED FOR READY INSERTION BETWEEN THE STRIPS AND HAVING GAS OUTLET APERTURES DIRECTED TOWARDS THE INLET END OF THE CHAMBER ADAPTED TO EMIT A BLAST OF GAS DIRECTED TOWARD THE INLET END OF THE CHAMBER TO BLAST THE ENTIRE WIDTH OF THE INWARDLY OPPOSED FACES OF BOTH STRIPS TO SWEEP DUST THEREFROM, THE GAS EMITTED FROM THE BLAST DEVICE FLOWING BETWEEN THE STRIPS IN THE DIRECTION OPPOSITE TO THAT OF TRAVEL OF THE STRIPS TOWARD AND OUT OF THE INLET END OF THE CHAMBER TO AVOID REDEPOSITION OF DUST ON THE STRIPS.
 3. THE METHOD OF CLEANING THE INWARDLY OPPOSED FACES OF TWO CONTINUOUS STRIPS TRAVELLING CONTINUOUSLY IN SPACED FACD-TO-FACE RELATION TO A REGION WHERE THEY ARE BROUGHT TOGETHER IN FACE-TO-FACE ENGAGEMENT, COMPRISING SWEEPING DUST FROM THE OPPOSITE FACES OF THE STRIPS BY A BLAST OF CLEAN GAS INTRODUCED INTO THE SPACED BETWEEN THE STRIPS AT A ZONE REARWARD OF THEIR REGION OF ENGAGEMENT AND DIRECTED REARWARD WITH RESPECT TO THE DIRECTION OF TRAVEL OF THE STRIPS, AND CONFINING THE SPACE BETWEEN THE STRIPS FROM THEIR REGION OF ENGAGEMENT REARWARD PAST THE ZONE OF THE INTRODUCTION OF THE GAS WHEREBY THE GAS IS CONFINED TO FLOW REARWARD IN THE SPACE BETWEEN THE STRIPS TO AVOID REDEPOSITION OF DUCT ON THE STRIPS AND OUTSIDE AIR IS EXCLUDED FROM BETWEEN THE CLEANED STRIPS. 